In order to improve the operating efficiency of cotton picker and solve the problems of low cotton picking efficiency and more cotton on the ground in the high-speed operation of cotton picker,the guider was optimized according to the working principle of the cotton picker guider and the picking head.According to the physical properties of cotton plants and the rational numerical analysis of pneumatic picking,the mathematical model of the guided pneumatic cotton suction device was established;the Fluent software was used to numerically simulate the pneumatic cotton suction device with different structure models,and the air flow characteristics and the cotton suction port of the cotton suction device were compared and analyzed.The result shows that when the cotton suction device is a cylindrical model,the speed of the cotton suction port is slightly different from the theory value,and the internal speed streamline is reasonably distributed;the model has the advantages of simple structure,convenient operation,stable performance,economical and practical.The results provides reference for the development of the pneumatic picking system of cotton pickers.